LED screen frames are generally connected through a lock catch structure. Limited by the field during installation of the LED screen or considering the visual effect, the jointed LED screen frames are usually staggered or meet a certain inclined angle relationship, for example, the LED screen frames connected in a ring-shaped or U-shaped way, but existing lock catch structures all carry out connection in a certain single direction. Different lock catch structures are applicable to connection at different angles. However, the existing lock catch structures fail to meet demands on multi-angle or angle transformation. Meanwhile, for the temporarily built LED screen frame, it is required to dismantle the LED screen frame after use. The lock catch structures on the frame are designed for different demands and thereof may have no other purposes, causing waste of resources.